The present invention relates to a display faceplate. More particularly, the present invention relates to a phosphor screen of a field emission display, wherein a layer of phosphor of the faceplate includes a plurality of openings.
A known display faceplate or phosphor screen, or, hereinafter, anode screen, of a field emission display comprises light permeable conductive material and phosphor layered respectively over a transparent substrate. The anode screen is disposed opposite a cathode emitter plate. Electrons emitted from emitters of the cathode emitter plate impact phosphor of the anode screen and excite the phosphor into illumination by phosphorescence or fluorescence.
Through continued use, electrons accumulate on the surface of the phosphor so as to reduce a voltage potential between a cathode emitter and the phosphor in proportion to the accumulated charge. This lower voltage reduces the acceleration of electrons emitted by the opposite emitters, in turn, limiting the ability of these electrons to obtain velocity and kinetic energy sufficient to excite the phosphor on impact. As a result, image illumination “turn-off” results. This phenomenon becomes more problematic as phosphor developments lead to phosphors of improved flatness, uniformity and resistance, and is especially problematic for monochrome phosphor screens.
In addition to possible image illumination turn-off, some charge of the accumulation is thought to migrate through the phosphor toward an underlying electrode of the anode screen. As the charge migrates through the phosphor, it may react electrochemically with compounds of the phosphor to produce gas contaminates. These gas contaminates are believed at least partially responsible for corrosion of emitters of cathode emitter plates of field emission displays. Furthermore, the electrochemical reactions are also thought to affect the color or intensity of the phosphor's phosphorescence.